The invention relates to a coating machine for the processing of chocolate and similar masses, having a frame and bearing therein a circularly driven grating belt for the reception of the articles to be coated, which is guided by deflectors and has a tensioning device, and with pieces of the coating machine, especially a shaking device, arranged under the upper run of the grating belt. Such a coating machine serves to cover the articles on the grating belt with chocolate, the chocolate flowing in surplus through the coating machine penetrating the grating belt and coming into contact with many parts of the coating machine. It may be a coating machine which has a covering station in which the liquid chocolate reaches the articles in free fall. The coating machine may also have a bottom covering station and/or a blower to blow off any surplus chocolate. Masses other than chocolate, such as fat-containing masses, coating masses and, caramel masses may also be processed with such a coating machine.
When changing the mass in the coating machine, that is when a dark chocolate has been processed and the following articles are to be coated with a light chocolate or even a white coating mass, the problem to remove the previously processed mass and to clean all parts which have been in contact with this mass, so that the new mass, for example a white coating mass, can be used in the coating machine, arises.
It is known that in order to complete such a change of masses the coating machine including the previously processed mass is heated and emptied by removing the previously processed mass using a recovery pump. Then a cleaning mass such as cocoa butter or some other fatty solution is introduced into the coating machine. The coating machine is then put into action without any articles passing through, so that the cleaning mass is continuously recirculated and passes through the machine station. By this the cleaning mass reaches a large fraction of the parts of the coating machine contaminated with the old mass and cleans these more or less completely by melting off the old mass. But not all parts of the coating machine are reached by the cleaning mass, so that the cleaning action is incomplete. The cleaning mass is removed from the coating machine at the end of the cleaning and used in the normal production of chocolate. Afterwards the coating machine can be filled with the new coating mass.
It is further known to fashion major parts of the coating machine from stainless steel and to follow the emptying of the coating machine of the old mass with a wet-cleaning using pressurized hot water. This wet-cleaning is problematic in several aspects. When applying the stream of hot water onto the grating belt a considerable spraying and distribution action takes place, so that the pieces of the coating machine below the upper run are reached only incompletely. The hot water necessarily introduced into the coating machine during this cleaning procedure causes a contamination which creates favorable conditions for bacteria. To counteract this danger, it is known to conclude the wetcleaning by a blow-drying procedure with hot air. By this, too, the parts of the machine are heated, and the drying process is carried out for a correspondingly long time. But even so, not all parts of the machine are reached by the drying procedure, and there is no possibility to check whether all parts that had come into contact with the water have been dried.
In German patent application P 42 09 966.8 a tempering and coating machine for different masses, especially white and non-white chocolate, is described, in which a production line for articles has two coating machines assigned to it which can alternately be introduced into the production line, where one coating machine is determined to be used for dark coating masses and the other coating machine for light coating masses, and are provided thus, so that in this way a changing of the masses is avoided and the problem of changing the masses has been solved by using two seperate coating machines. This solution is possible only when there is enough room for the coating machines to the left and to the right of the production line, though. in many cases this room is not available, though, especially when several parallel production lines for articles are installed.
For the changing of masses in a coating machine it is also known to cut open the grating belt transversely to its direction of travel and thus to open the loop of the grating belt, so that the aggregates located below the upper run of the grating belt are well accessible for cleaning. Cleaning masses, which may consist of cocoa butter or, again, of hot water, have to be used for this cleaning. In this case, too, the cleaning is correspondingly cumbersome, elaborate, and unsure. Especially since the severed grating belt has to be reassembled.